Intercropping and canopy closure help with weed and pest suppression

During the second quarter of Year 1 (Y1|Q2), the project progressed from establishment to active field execution, data generation, and early analytical insight. Key research activities during this period focused on the implementation and maintenance of field experiments across all study locations.

Comprehensive weed data (density and biomass) were collected across treatments, alongside crop data for maize and cowpea, capturing critical growth stages. These datasets represent the core empirical outputs of the project and are currently undergoing collation, cleaning, and preparation for statistical analysis.

Preliminary field observations indicated lower weed pressure and reduced pest incidence, particularly Fall Armyworm (FAW), in plots where cowpea intercropping enhanced soil cover. These observations provide early evidence supporting the role of intercropping and canopy closure in weed and pest suppression, with direct relevance for climate-resilient smallholder cropping systems. Significant progress was also made in strengthening the project’s climate component. Meteorological data coverage was expanded from the ten years reported in Y1|Q1 to 56 years of historical climate data, substantially improving the robustness of planned analyses linking climate variability to cropping system performance.

In terms of outputs, two research manuscripts were developed. One manuscript has been submitted for presentation at the International Water Association (IWA) Congress, while the second is currently undergoing internal review by co-authors, with both outputs targeted for dissemination at an international conference.

Stakeholder engagement continued, with sustained interaction with farmer groups, meteorological units, and research institutions. These engagements have informed the planning of a stakeholder dissemination workshop scheduled for Year 2.

Maize–cowpea intercropping field plot in Kwara State, Nigeria, showing crop establishment and early ground cover development.

The primary challenge encountered was heightened insecurity in rural field locations, including parts of Kwara State. To ensure the safe completion of field activities, security personnel were engaged, with associated costs temporarily covered using banked (previously unutilised) project funds. Provision to replenish these banked funds has been captured in the approved Year 2 budget, with reimbursement scheduled for Y2|Q1. No delays to field data collection resulted from these measures. Overall, Y1|Q2 represents a period of strong execution, successful data generation, and tangible scholarly outputs, positioning the project well for advanced data analysis, synthesis, and dissemination in subsequent quarters.

A snake was encountered during routine field data collection in the experimental plot; field activities were temporarily paused, and appropriate safety measures were taken before resuming work.

During a routine field data-collection visit, an unexpected but memorable incident occurred as the research team prepared to take measurements in a cowpea–maize intercropping plot. A snake was observed resting beneath the dense cowpea canopy, likely drawn to the shaded, cooler microclimate created by the ground cover. The encounter prompted an immediate pause in data collection and careful reassessment of the area to ensure the safety of the research team before proceeding. While no harm occurred, the experience served as a practical reminder of the realities of conducting field-based agricultural research in natural farming environments. Beyond its novelty, the incident also reinforced an important agronomic observation: the cowpea intercrop created substantial soil cover and modified microhabitats, with implications not only for weed suppression and moisture conservation but also for biodiversity interactions within cropping systems. The incident was documented photographically and included in the field documentation. Overall, it added a human dimension to the fieldwork experience while underscoring the importance of situational awareness and safety during on-farm research activities.

Dr Judith Adejoke Falola-Olasunkanmi reporting on her progress for the following research project: Resilient Cropping Systems for African Smallholders: Integrating Weed Management, Climate Adaptation, and Agronomic Innovations.

Edited by Heidi Sonnekus & Leti Kleyn for the FAR-LeaF programme.